Valve bag



H. E. LEE

May 16, 1950 VALVE BAG Original Filed Nov. 12, 1940 INYENTOR. HA RRY E. LEE. 004M ATTORNEYS.

Mani;

v l i SLIT Harry E. Lee, Oswego, N. Y., assignor to St. Regis Paper Company, New York, N. Y., a corporation or New York Original No. 2,478,113, Iatcd August 2, 1949, Serial No. 619,149, September 28, 1945. Application for reissue January 27, 1950, Serial No. 140,940

I 3Claims. (Cl. 22962.5)

Matter enclosed in heavy brackets [.1 appears in the original patent but forms reissue specification; matter printed in italics indicates the additions made by reissue This invention relates to multi-ply bags and, more particularly, to bags wherein one corner is folded in to form a valve.

An important feature of the invention resides in extending at least one ply of the bag inwardly beyond the inner edge of the remaining plies oi the valve, thereby forming an integral flexible valve extension which is pushed upwardly against the bag walls, when the bag is filled, by the pressure of the material within the bag, to thereby seal the valve opening and prevent material from sitting out therethrough. Preferably, this valve extension should be formed on an intermediate ply of the bag since, if the outer ply is extended, then in the process of manufacturing the bag lengths from a continuous tube with a minimum of wastage, an exposed area of the outer ply oi one bag length would have to be cut away to provide the area of material for the extended ply of the next adjacent bag length, and of course such a gap or cut out area in the outer ply would be undesirable. Also, it the inner ply were extended, a similar gap or cut out area would occur in the inner ply of the adjacent bag length and would permit material to leak from the inside of the bag into the space between the plies. with the intermediate ply extended, the corresponding cut out area on the next adj acent tube length, will be concealed by the inner and outer plies. However, with some types of bags, such for example as pasted bags, the extension may advantageously be formed on the irmer or outer ply especially if suchextension is comparatively short with respect to the depth of the valve.

According to the invention, the integral valve extension is preferably of beveled or tapered configuration when it is spread out in a plane, with the tapered portion directed inwardly of the valve. When a valve extension is formed on a gusseted bag, slits may advantageously be formed in the extension along the fold lines which define the gusset of the bag, these slits permitting the bag to be readily filled by'material forced through a filling spout and thence passing through the lower slitted portion of the extension into the bag. Such slits are further advantageous in iacilitating closure of the valve after the bag has been fllled since they permit the flexible portions of the extension to readily overlap without wrinkles and thusseal the bag.

Various further and more specific objects, features and advantages of the invention will appear from the description given below taken in connection with the accompanying drawings illustrating, by way of example, a preferred form of to the bag walls.

the invention. The invention consists in such novel features and combinations as may be shown and described in connection with theexample of the invention herein disclosed In the drawings: Fig. 1 is a sectional view, with portions of the bag walls broken away, showing the construction g of the novel valve bag;

Fig. 2 is a view of the valve extension with the bag walls spread apart; 1

Fig. 3 is a perspective view of the novel valve bag of the invention;

Fig. 4 is a developed view of edge portions of the intermediate ply of the bag tube as cut in accordance with the invention; and

Fig.5 is a perspective view showing the shape of such intermediate ply at the region of the top corner ,9! the bag opposite from the valve corner.

Referring to the drawings in further detail, a three ply bag is shown at in as beingformed fromouter, intermediate and inner plies II, I!

and it. Although a three ply bag is shown for the valve, and the edges i8 may be substantiallyv parallel to the edge surfaces {4 and I6 of the";

bag. The upper part of the valve may be de: fined by the wall portions i9 and the diagonal fold lines 20 where the valve is integrally joined Below the lines 20, the valve walls may merge as at 2| toward the bottom fold line II. It will be apparent that the valve walls are of generally V-shap'ed cross section when the bag is empty and in collapsed position.

According to the invention, the middle plyl! may extend inwardly as at 25 beyond the conventional inner edges Hi to thereby form a. flexible integral extension of the valve. This extensionmay be tapered as at 26 with such tapered portions merging into the inner end portions 21 of to allow material readily to be discharged, in the usual manner, from a filling spout inserted into the valve to thereby fill the bag. The extension no part of this mayalsobeslittedasatllsuchslitsbeins formed along the gusset fold lines It, II and it before the bag corneris folded inwardly to form the valve.

It will be understood that, after the bag is filled, the material within the bag presses the valve walls and the extension upwardly to seal the bag and prevent the contents thereof from leaking out through the valve. II, I! are advantageous in that they permit the flexible portions of the valve extension to overlap without wrinkles whereby a more effective seal and closure isobtained.

Methods for forming the novel valve bag of this invention are described and claimed in U. 8. Patent No. 2,392,094, granted January 1, 1946, on my copending divisional application Ser. No. 365.233. As indicated hereinabove, and in said copending application, such methods in general may comprise forming the multi-ply bag lengths from a continuous multiwall tube, in such manner that the extended flexible valve flap of the intermediate ply is cut from the edge of the intermediate ply of the next adjacent bag to be cut from the continuous tube. Thus, as disclosed in said patent, at the top corner of the bag, opposite from the valve corner, an area of the intermediate ply is cut out to provide the material for the extension fiap of the next bag, such area being of the same outline or at least as extensive as the valve extension flap. This is shown in Fig. 4, which is a developed view partly broken away, of the extended and cut-out edge portions of the intermediate ply. In the righthand portion of this figure the parts are identified with the same reference characters as for corresponding parts in Fig. 3. At the lefthand side of this figure the various corresponding parts of the outline of the cut-out portion at the top corner of the bag opposite from the valve corner are also identified by the same reference numerals accompanied by prime marks. In the perspective view of Fig. 5 the shape of the intermediate ply at the top corner of the bag opposite from the valve corner is shown, this figure indicating the relative positions which the various portions of the outline oi the cut-out portion will assume. The positions which will be assumed by the and edges of thejnner and outer plies at this corner are indicated by dotted lines in Fig 5. It will be understood that the cut-out area of the intermediate ply will be fully covered by the inner and outer plies so that there will be no oportunity for sifting of the bag contents down betweemthe plies due to there being a cut-out area in the intermediate ply. Such cutout area not only provides the material for the valve extension flap of the next adJacent bag, but also has the advantage important in some cases, of eliminating four thicknesses of paper at this gusseted top corner so that the corner is made more flexible and thus does not so rigidlyprotrude as to tend to cause cracking of the paper adjacent the corner when the corner is jammed during rough handling of the bag.

It will be obvious from the foregoing descrip- 65 tion that the size and shape of the valve extension may be varied without departing from the scope of the invention and that such an extension may be formed on more than one ply of the bag, if desired. Moreover, the construction and arrangement of the slits may be changed and, in some cases, particularly in pasted bags, they may be omitted altogether. According to another aspect of the invention, the non-extended plies of In this connection, the slits l ample, it will be understood by those skilled in nerand this is preferably done by applying a line at sgzcghing as at ll, Fig. 1, to the open end of While the invention has been described in detail with respect to a particular preferred exthe art after understanding the invention that various changes and modifications may be made without departing from the spirit and scope of the invention, and it is intended therefore in the i5 appended claims to cover all such changes and modifications.

Whatisclsimedasnewanddesiredtobe secured by Letters Patent is:

1. A multi-ply valve bag having its body portion formed of at least three flattened tubes gusseted at their sides and including an inner tube surrounded by an intermediate tube and an outer tube, the top corner portion of the intermediate tube atthe valve corner extending substantially beyond the inner and outer tubes and such corner being folded inwardly of the bag to form a valve with the extension of the intermediate tube providing a flexible valve flap extension adapted to be pressed up against the inside top portion of an the bag by the contents of the bag when filled to check sifting of such contents through the valve, the intermediate tube at the top corner onposite from the valve corner being formed with a cut-out gusset area extending down from its upper edge. such area corresponding in extent to that of said flap extension and being covered internally and externally of the bag by the inner and outer tube walls.

2. A multi-ply valve bag having its body portion 40 formed of at least three flattened tubes gusseted at their sides and including an inner tube surrounded by an intermediate tube and an outer tube, the top corner portion of the intermediate tube at the valve corner extending substantially beyond the inner and outer tubes and such corner being folded inwardly of the bag to form a valve with the extension of the intermediate tube pro-* viding a flexible valve flap extension adapted to be pressed up against the inside top portion of the bag by the contents of the bag when filled to check sifting of such contents through the valve, the intermediate tube at a corner on the side of the bag opposite from the valve corner being formed with a cut-out gusset area extending from its end edge, such area substantially corresponding in extent to that of said flap extension and being covered internally and externally of the bag by the inmr and outer tube walls.

3. A multi-plg valve bag having its body portion formed of at least three flattened tubes, in-

cluding an inner tube surrounded by an intermediate tube and an outer tube, the tube ends being secured together to close the bag, the top corner portion of the intermediate tube at the valve corher extending substantially beyond the inner and outer tubes and such corner being folded inwardly of the bag to form a valve with the extension of the intermediate tube providing a flexible valve flap extension adapted to be pressed up against a the inside top'portion of the bag by the contents of the bag when filled to check sifting of such contents through the valve. the intermediate tube at another corner being formed with a cut-out urea extending from its end edge, such areavsubthe valve portions It may be made shorter or-even 7 stantiallg corresponding in ertent to that a! said W5. flap extension and being eovered internally and externally of the ban buthe end portion: of the UNITED STASES PATENTS immllmd outer tube my 1;, LEE; l j g iJ 1433193 3333233 gf r ff jjillil531311; 132? BEFERENFES CITE-D 2346:2922 Coty Apr. 11: 1944 m3? $ifi$i$fg$ggfi 31331332v fifiiiiy' iaziiiiiiii'afiifiij i323 

